Detailed-balance tests of time-reversal invariance (TRI) with charged-particle resonance reactions are reexamined from the view that there may be large enhancement of TRI violation near two interfering resonances. In our proton resonance data on ${}_{}{}^{23}{}_{}{}^{}\mathrm{Na}$, ${}_{}{}^{27}{}_{}{}^{}\mathrm{Al}$, ${}_{}{}^{31}{}_{}{}^{}\mathrm{P}$, ${}_{}{}^{35}{}_{}{}^{}\mathrm{Cl}$, and ${}_{}{}^{39}{}_{}{}^{}\mathrm{K}$ targets, there are 41 pairs of adjacent resonances with the same angular momentum and parity. Using experimental resonance parameters, the difference in the differential cross sections for the (p,${\mathrm{\alpha }}_0$) and (α,${\mathit{p}}_0$) reactions was calculated for each of these resonance pairs. An appropriate figure-of-merit involving both the difference of the two cross sections and the magnitudes of the cross sections was determined for each resonance pair. Both the differences and the figures-of-merit show very strong dependence on energy, angle, and the particular pair of resonances; the relative sensitivity varies by many orders of magnitude. These results suggest that suitably chosen charged-particle resonance tests of TRI violation would be much more sensitive than previous detailed-balance tests.

• Received 23 August 1993

DOI:https://doi.org/10.1103/PhysRevC.49.411